/* 基础按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 500;
  text-align: center;
  white-space: nowrap;
  vertical-align: middle;
  user-select: none;
  border: 1px solid transparent;
  padding: calc(var(--space-unit) * 1.5) calc(var(--space-unit) * 3);
  font-size: 1rem;
  line-height: 1.5;
  border-radius: var(--radius);
  transition: all 0.2s ease-in-out;
  cursor: pointer;
  min-width: 48px;
  min-height: 48px;
  position: relative;
  overflow: hidden;
}

.btn:focus {
  outline: 0;
  box-shadow: 0 0 0 3px rgba(51, 202, 187, 0.25);
}

/* 主按钮 */
.btn-primary {
  color: white;
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

.btn-primary:hover {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
}

/* 次按钮 */
.btn-secondary {
  color: var(--primary-color);
  background-color: white;
  border-color: var(--primary-color);
}

.btn-secondary:hover {
  background-color: var(--primary-light);
}

/* 幽灵按钮 */
.btn-ghost {
  color: var(--primary-color);
  background-color: transparent;
  border-color: transparent;
}

.btn-ghost:hover {
  background-color: rgba(51, 202, 187, 0.1);
}

/* 禁用状态 */
.btn.disabled,
.btn:disabled {
  opacity: 0.65;
  pointer-events: none;
}

/* 按钮大小 */
.btn-sm {
  padding: calc(var(--space-unit) * 1) calc(var(--space-unit) * 2);
  font-size: 0.875rem;
  min-height: 36px;
}

.btn-lg {
  padding: calc(var(--space-unit) * 2) calc(var(--space-unit) * 4);
  font-size: 1.125rem;
  min-height: 56px;
}

/* 按钮组 */
.btn-group {
  display: inline-flex;
  vertical-align: middle;
}

.btn-group > .btn:not(:first-child) {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  margin-left: -1px;
}

.btn-group > .btn:not(:last-child) {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}